异位热脱附技术在农药污染土壤的应用研究

Study on the Pesticide Contaminated Soil with Ex-situ Thermal Desorption

我国是农药生产和使用大国,随着城市产业结构调整升级,在许多城市遗留了大量因企业关闭、搬迁遗留下的高浓度高毒性复合污染场地,涉及有机氯类农药污染、有机磷类农药污染等,给场地及周边生态环境和人体健康带来了严重风险隐患。文章以异位热脱附技术修复某农药厂污染土壤为例,通过中试研究影响异位热脱附效率的工艺参数。结果表明,加热温度为400℃,有效停留时间为20 min,水分≤20%,粒径≤30 mm时,土壤中α-六六六等污染物脱附率均在99.5%及以上。同时,可为后续大规模工程实施提出了技术参考。

China is a big producer and user of pesticides,with the adjustment and upgrading of urban industrial structure,a large number of soils are contaminated by high concentrations of highly toxic composite pesticides due to petrochemical enterprises closured and relocated.The main pollutants including organochlorine pesticides(OCPS),organophosphorus pesticides and so on.In this paper,the ectopic thermal desorption technique was used to remedy contaminated soil in a pesticides plant.Pilot scale test was carried out to determine the process parameters,which can affect the thermal desorption efficiency.The results showed that the desorption rate of pesticide such asα-benzene hexachloride in the soil was 99.5%or more when the thermal desorption temperature was 400℃,the residence time was 20 min,the soil moisture content was up to 20%,and particle size of soil was up to 30 mm.At the same time,it could provide reference for large-scale engineering implementation.